2025 Proffered Presentations
S258: VESTIBULAR SCHWANNOMA MANAGEMENT PARADIGM SHIFT: HAS LESS THAN TOTAL RESECTION HAD AN IMPACT ON THE NEED FOR FURTHER TREATMENT AND FACIAL NERVE OUTCOMES?
Hala Kanona, Dr1,2; Jigi Moudgil-Joshi, Dr2; Ankit Patel, Dr1; Simon Williams, MBChB MRCS3; Mariella Fortune-Ely, Dr1; James Arwyn-Jones, Dr6,7; Nish Mehta, Dr1,8; S Jawad, Dr1; Patrick Grover, Dr3,4; Robert Bradford, Dr3; Sherif Khalil, Dr1,2; Shakeel R. Saeed, Professor1,2; 1The Royal National ENT Hospital, University College London Hospitals, London, United Kingdom; 2The Royal National ENT Hospital and National Hospital for Neurology and Neurosurgery, University College London Hospitals, London, United Kingdom; 3Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, UK; 4Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, London, UK; 5The Francis Crick Institute, London, UK; 6University College London Great Ormond Street Institute of Child Health, London, United Kingdom; 7Great Ormond Street Hospital, London, United Kingdom; 8UK NIHR UCLH BRC Deafness and Hearing Problems Theme, Ear Institute, University College London, London, UK
BACKGROUND: Historically, primary resection of vestibular schwannoma (VS) aimed for complete tumour removal. In more recent years there has been a shift towards less than total resection to balance tumour control against facial nerve preservation and quality of life.
OBJECTIVE: To assess outcomes for primary surgical resection of VS by examining whether less than total VS resection impacts further treatment and facial nerve outcomes.
METHODS: 186 patients with histologically confirmed VS, that had undergone primary surgical resection between 2009 and 2023, were included in the study. Tumour resections were stratified as Gross Tumour Resection (GTR) representing no remnant tumour, Near-Total Resection (NTR) representing remnant tumour of <5%, Sub-Total Resection (STR) representing <10% remnant tumour and Partial Resection (PR) representing >10% remnant tumour. House Brackmann (HB) scores were recorded to assess facial nerve outcome.
RESULTS: Primary surgical approach was retrosigmoid in 80 patients (43%) and translabyrinthine in 106 patients (57%). Degree of resection, determined by the XYZ tumour volume, was 38 GTR (20.4%), 60 NTR (32.3%), 28 STR (15.1%) and 60 PR (32.3%). 126 patients (67.7%) required no further surgery, while 60 patients (32.3%) underwent additional interventions. Among these, 47 patients (78.3%) had one additional treatment (42 Gamma Knife, 5 revision surgeries). Tumour size at CPA was marginally significant in predicting the number of retreatments (p=0.063), with each unit increase in size increasing retreatment frequency by 1.2%.
Postoperative Gamma Knife (GK) was required in 51 patients (27.4%), with the highest rates being in PR patients (48%). No patients with initial surgery followed by elective GK required further surgery. Resection type significantly affected the number of treatments, with GTR and NTR associated with fewer retreatments.
Facial nerve outcomes at 12 months were ‘good’ in 80.6% of patients (HB 1-2), with 88% having normal facial function. 'Intermediate' (HB 3) and 'poor' (HB 4-6) outcomes were each observed in 9.7%. Resection type significantly impacted facial nerve outcomes (p<0.001), with NTR associated with worse outcomes compared to PR (p=0.014). Increased preoperative tumour volume (mm3) was a significant predictor of worse HB outcomes in the NTR group.
The number of retreatments significantly predicted the type of resection, with more retreatments being associated with less extensive resections (NTR, STR, PR) compared to GTR (p<0.001). However, more retreatments were not significantly associated with worse HB outcomes overall (p=0.063). For those patients who underwent STR or PR, 17 had surgery (19.3%). Those who did not undergo surgery had significantly better 12-month HB outcomes (Estimate = -1.825, p = 0.001), with significant differences between HB 3 and 4 (p = 0.002) and HB 4 and 5 (p = 0.002). Larger maximum tumour size in the CPA (p = 0.040) and higher preoperative tumour volume (p = 0.026) were significantly associated with worse 12-month HB outcomes in this group.
CONCLUSION: The treatment and management of VS has dramatically evolved over the last decade. Despite higher rates of additional intervention in STR and PR, good facial nerve preservation rates have been achieved thereby supporting a strategy of less than total resection.